Input interpretation
cerium(III) iodide nonahydrate | molar mass
Result
Find the molar mass, M, for cerium(III) iodide nonahydrate: M = sum _iN_im_i Plan: • Write the chemical formula and gather atomic masses from the periodic table. • Determine values for N_i and m_i using these items. • Finally, compute the mass. Write the chemical formula: CeI_3·9H_2O Use the chemical formula to count the number of atoms, N_i, for each element: | N_i Ce (cerium) | 1 H (hydrogen) | 18 I (iodine) | 3 O (oxygen) | 9 Look up the atomic mass, m_i, in g·mol^(-1) for each element in the periodic table: | N_i | m_i/g·mol^(-1) Ce (cerium) | 1 | 140.116 H (hydrogen) | 18 | 1.008 I (iodine) | 3 | 126.90447 O (oxygen) | 9 | 15.999 Multiply N_i by m_i to compute the mass for each element. Then sum those values to compute the molar mass, M: Answer: | | | N_i | m_i/g·mol^(-1) | mass/g·mol^(-1) Ce (cerium) | 1 | 140.116 | 1 × 140.116 = 140.116 H (hydrogen) | 18 | 1.008 | 18 × 1.008 = 18.144 I (iodine) | 3 | 126.90447 | 3 × 126.90447 = 380.71341 O (oxygen) | 9 | 15.999 | 9 × 15.999 = 143.991 M = 140.116 g/mol + 18.144 g/mol + 380.71341 g/mol + 143.991 g/mol = 682.964 g/mol
Unit conversion
0.68296 kg/mol (kilograms per mole)
Comparisons
≈ 0.95 × molar mass of fullerene ( ≈ 721 g/mol )
≈ 3.5 × molar mass of caffeine ( ≈ 194 g/mol )
≈ 12 × molar mass of sodium chloride ( ≈ 58 g/mol )
Corresponding quantities
Mass of a molecule m from m = M/N_A: | 1.1×10^-21 grams | 1.1×10^-24 kg (kilograms) | 683 u (unified atomic mass units) | 683 Da (daltons)
Relative molecular mass M_r from M_r = M_u/M: | 683